Controlling the Morphology and Size of GdF₃:RE³⁺ (RE = Dy, Tb, and Sm) by pH Value: Growth Mechanism, Energy Transfer, and Luminescent Properties

In this paper, the synthesis of rare earth fluoride GdF 3 multiform morphologies via a glutamic acid hydrothermal method has been fulfilled. The size and shape of the products could be tuned just by adjusting the pH values of the initial reaction solutions. The morphologies for the products include spindle-like, peanut-like, submicrometer flowers, and nanoflowers. Additionally, the possible formation mechanism of multiform morphologies was proposed. Furthermore, we systematically investigate the luminescence properties of different lanthanide ions (Dy 3+, Tb 3+, and Sm 3+ ) in GdF 3 host. In the GdF 3:Tb 3+,Sm 3+ system, the energy transfer process fromTb 3+ to Sm 3+ was demonstrated to be resonant type via a dipole–dipole mechanism. Most interestingly, white light and multicolor light have been obtained in Tb 3+ and Sm 3+ coactivated or Dy 3+,Tb 3+,Sm 3+ tridoped GdF 3 phosphors. The results show that the obtained nanophosphors have a promising application in display and lighting fields.